Improved bridge



E lllfill gi/M@ und@ NAPETERS. PHOTO-LITHOGRAPHER, WASHINGTON, D4 C.

ditched gasten' DAVID MCOURDY, OF OTTAWA, OHIO.

l Letters Patent No. 104,869, dated J'nnc 28, 1870; antcdated fanali', 1870.

The Schedule'referred to in these Letters Patent and making part of the same To alll whom it may concern:

Be it known that I, DAVID MUCURDY, of Ottawa, in the county of Putnam and in the State of Ohio, have invented certain new and useful Improvements in Bridges; and do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawing and to the letters of reference marked thereon, making a part of this specification.

Ihe nature of my invention consists -in the construction and arrangement of a bridge, having an oval arch, with the door on top.

In order to enable others skilled in the art to which my invention appertains to make and use the same-,I will now proceed to describe its construction and operation, referring to the annexed drawing, in which- Figure 1 is a plan view of the bridge 5 Figure 2 isa side view of the same; and

Figure 3 is a crosssection of one of the girders composing the arch.l

Each of t-he girders of which my -arcll is composed, is formed of two bars A A, running parallel, at a suitable distance apart, and having blocks B B inserted Vbetween them, at convenient points, through which blocks bolts are passed to secure the bars A` A togather.

'lbe girder thus formed is made in an ovalshape, and, when three or more-of these girders are placed in position to form the arch, they are connected on the under side 'by cross-ties C O, placed at any desired distance apart.

The cross-ties O O are secured to the bars A A in the following manner: Clamps a, a are placed across the upper side of the bars A A, and a rod, b, passed through the same, between the bars and through lthe cross-tie, said rodbeing fastened by nuts d (l, one above the cap a and the other below the cross-tie O.

The lower ends of the rods b l form loops or eyes, which are all on a line with the ends of the bars A A, so that the chord D mayp'ass through the same.

lhe chord D passes'through the shoes E E, pnt on the ends ot'fthe bars A A, and is secured by nuts.

At suitable points across the bars A A, between the caps or clamps a c, are placed other clamps ec,- throngh which are passed rods i @secured by nuts f f on top of the clamps, said rods passing downward bctween the bars A A, and are, at their lower ends, also provided with eyes or stirrups. These eyes or stirrnps are on a`linc higher than the line of eyes at the lower ends of the rods b b.

The chord lD passes also lthrough the eyes or. stirrups formed on the lower ends of the rods t i, and is, consequently, drawn upward at those points. By this means, a portion of the tensile strength 'of thechord is transferred upward to the girder, so as to resistcoinpression, the rise to be propcrtioned to the span.

yI use three or more girders, of the form herein-described, so that, in crossing with a load, the weight will always be on two girders.

The floor is to be secured on top of the girdcr by means of clamps at the sides, and the railing will be put on by staples 011 the sides, like those on platformcars.

Y 'Ihe girders may be made of wood or met-al, and un- 2. In combination with the clamps a a, rods b b, and

nuts d d, the clamps c c, rods i @diagonal cross-tics G, and nuts ff, all constructed as described, so as to transfer the tensile strength of the chord D upward, substantially as herein set forth. Y

3. The combination and `arrangement of the bars A A, blocksIB'B, cross-ties C C, shoes E E, chords D D, and the clamps andvrods herein mentioned, for

transferring the tensile strength of the chords upward,

and with or without the cross-ties G, substantially as herein setforth.

In testimony that I claim the foregoing I have hereunto set my hand this 8th day of October, A. D.

DAV ID MCGURDY.

Witnesses: A. l

J. J. MOORE, OoR'rUs Ewnve. 

